热激发效应对界面摩擦的影响

摘要

论文主要从微观角度研究摩擦热产生的机理及摩擦热对摩擦性能的影响.依据固体物理学中原子热振动理论,以界面摩擦为研究对象,从分析界面原子的受迫振动出发,得出界面摩擦过程中原子的振动实际上是自激振动和受迫振动的叠加,界面原子在非平衡状态下的热振动将导致声子的激发和湮灭,进而导致摩擦热的产生,摩擦界面的温度升高.然后,从温度对界面原子能级分布和跃迁的影响角度探讨了热激发效应对界面摩擦的影响,分析得出如下结论：温度低时,界面原子处在激发态的概率随着温度的升高而增加,导致摩擦系数随温度增加而增加;温度在100 K附近界面原子处在激发态的概率出现峰值,导致摩擦系数出现峰值;当温度高于临界值后,摩擦系数随温度的升高反而会降低.最后将本文的理论分析的结果与他人的实验结果对比,显示两者的趋势一致,表明本文提出的理论和方法可行.%In the present paper,by analyzing the microscopic mechanism of forced vibration of interfacial atoms,it is shown that the atomic vibration is actually the superposition of the self-excited vibration and the forced vibration.The phonon excitation and annihilation due to the thermal vibration of the interfacial atoms in a non-equilibrium state are studied based on solid state physics and quantum mechanics.Then,the temperature effect on vibration energy levels of interfacial atoms are investigated,which shows that when the temperature is low,the probability for a quantum harmonic oscillator being in an excited state rises with temperature,causing the friction coefficient to rise with temperature.When the temperature is around 100 K,the probability for a harmonic oscillator being in the excited state reaches the peak,causing a peak friction coefficient at this point.When the temperature is above 100 K,the friction coefficient decreases with temperature.The trends of our analytical results and the experimental results of others are the same, indicating that the proposed theory and method are feasible.